Non-polymer fiber

There are many different types of fibers. Most fibers have diameters greater than 1 micrometer, and they can be divided into polymer fibers and non-polymer fibers. Polymer fibers include synthetic polymer fibers and natural polymer fibers. Synthetic polymer fibers are made from polymers synthesized from raw... 

Chapter 6 addresses the stracture of non-polymer fibers. A wide range of non-polymer fibers, such as carbon, glass, silicon carbide, boron, asbestos, and metal fibers, now is available commercially. Compared with polymer fibers, nonpolymer fibers often are stronger, stiffer, more heat resistant, and nonflammable. However, except for metal fibers, non-polymer fibers also are characterized by their brittleness. These property characteristics are directly related to the atomic arrangement and the defect stracture of non-polymer fibers. Chapter 6 discusses the stracture of two most used non-polymer fibers caibon and glass fibers. 

Non-polymer fibers can be produced by many different methods, depending on the type of materials used. For example, carbon fibers often are made by high temperature treatment of carbon precursors in an inert atmosphere. Glass fibers and some ceramic fibers can be directly spun from their melts. Ceramic fibers also can be obtained by the calcination of ceramic precursor fibers or by the chemical vapor deposition of precursor gas on a carbon fiber substrate. Chapter 11 focuses on the formation of carbon and glass fibers. 

However, the relaxation times of most non-polymer fibers are significantly greater than the time scale of normal observations, and hence it is hard to observe their viscoelastic behavior at room temperature. On the other hand, polymer fibers have relaxation times that are comparable to the time scale of observation, and they easily display viscoelastic behavior. Chapter 16, therefore, focuses on the viscoelastic properties of polymer fibers. 

Compared with polymer fibers, what are the unique features of non-polymer fibers ... 

Viscoelasticity is the property of materials that exhibit both viscous and elastic responses under applied stress. Viscoelastic properties haven been observed throughout recorded history. For example, archers in ancient time knew they should never leave their bows strong when not in use because the tension in the bowstring would decrease over time. The first scientific study on the viscoelastic properties of fibers is probably by Weber, who noted in 1835 that silk fibers under tension presented an immediate deformation and a delayed extension that increased with time. As a matter of fact, all materials can exhibit elastic and viscous characteristics simultaneously if the time scale of observation is comparable to the relaxation times needed for large-scale atomic rearrangements in these materials. However, the relaxation times of most non-polymer fibers are significantly greater than the time scale of normal observation, and hence it is hard to observe their viscoelastic behavior at room temperature. On the other hand, polymer fibers have relaxation times that are comparable to the time scale of observation, and then they easily display viscoelastic behavior. This chapter, therefore, focuses on the viscoelastic properties of polymer fibers. 

Specific heat indicates the ability of a material to store energy in the form of heat. The specific heats of some fibers and other materials are shown in Table 17.1. In general, polymer fibers have higher specific heats than non-polymer fibers and most other materials (except for water, ice, and organic solvents) because a large amount of energy is needed to excite the vibrational, rotational, and translational motions of polymer chains in order to raise the temperature. As a result, textile fabrics could give serious bums when they melt and are in contact with skin. 

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